EPE Association: EPE 2017 - DS1d: Hard & Soft Switching techniques I

EPE 2017 - DS1d: Hard & Soft Switching techniques I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 02: Power Converter Topologies and Design > EPE 2017 - DS1d: Hard & Soft Switching techniques I

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   A Transformer-less Single Phase Inverter For photovoltaic Systems
By Ali MOSTAAN [View]
[Download]

Abstract: A single phase transformer-less inverter is introduced in this paper. The negative polarities of the input voltage and output terminal have common ground. Therefore, the leakage current problem that is common in PV systems is eliminated naturally. In addition, the proposed inverter has fewer components compared with its counterparts and only one switch conducts during the active states which enhance the inverter efficiency. The proposed inverter is analyzed in details and compared with some existing topologies. The performance of the proposed inverter is validated using the simulation results.

   Comparison of Switching Devices for a Zero-Current Switched Class E based Automotive Inductive Charging Converter System
By Patrick NIEFNECKER [View]
[Download]

Abstract: The zero-current switched Class E converter topologies offer great potential regarding energy efficiency and cost effectiveness for automotive inductive charging applications. In comparison to the Class D converter topologies the resonant current is not flowing in the semiconductor switching devices, reducing the system's sensitivity to variations of the charging-coil coupling. In this paper the performance of SiC MOSFETS are investigated and compared to the performance of a selected Si IGBT. A simplified test set-up with similar behavior as the inductive charging circuit has been developed that allows an accurate adjustment of the operating conditions of the switching devices. The waveforms obtained from the measurements confirm the theoretical predictions very well. It is shown that low switching losses are achieved mainly related to the discharge of the output capacitance of the SiC MOSFET. The results also show the suitability of the proposed topology for the given application.

   Discontinuous Interleaving of Parallel Inverters for Efficiency Improvement
By Bjørn RANNESTAD [View]
[Download]

Abstract: Interleaved switching of parallel inverters has previously been proposed for efficiency/size improvements of grid connected three-phase inverters. This paper proposes a novel interleaving method which practically eliminates insulated gate bipolar transistor (IGBT) turn-on losses and drastically reduces diode reverse recovery losses. The reduction in switching losses are obtained by interleaving two parallel inverter branches so that only one branch conducts the load current at a time. By placing saturable inductors between the parallel branches, soft switching may be obtained, and thereby overall power module losses are reduced. The modulation strategy is suited for converters with doubly fed induction generators (DFIG) for wind turbines, but are not limited hereto. Improvement of switching performance are measured and operational efficiency improvements are calculated and verified in an operating inverter.

   Evaluation of GaN Transistors in a Phase-leg Configuration for Motor Drive Applications
By Jennifer LAUTNER [View]
[Download]

Abstract: This paper presents the evaluation of a 650V GaN transistor which is used for a motor drive application.The influence of parasitic effects, e.g. cross conduction and stray inductances, in a GaN phase-legconfiguration are analyzed by means of simulation. Additionally, experimental results of the switchingtransients are shown. Furthermore, measurement issues and other practical challenges are discussed

   Loss-Oriented Asymmetrical PWM Technique for High-frequency Impedance Source Converters
By Piotr MAJTCZAK [View]
[Download]

Abstract: The paper presents four asymmetrical pulse width modulation techniques for three-phase impedance source converters operating at high switching frequencies. The concept behind all proposed methods is to introduce single-phase shoot-trough states and reduce commutation currents of fast-switching SiC MOSFETs. All techniques are explained and verified by means of Saber simulations and laboratory experiments. Advantages and negative aspects, such as increased on-state losses, are discussed in reference to state-of-the-art techniques. Performed measurements at 100kHz/6kVA model of the quasi-Z-source inverter show that in selected operation areas new techniques lead to slightly improved efficiency without loss of input and output currents quality.

   PROPOSAL OF A NEW SOFT SWITCHING SYSTEM FOR THREE-PHASE VOLTAGE SOURCE INVERTERS
By Zbigniew SZULAR [View]
[Download]

Abstract: The paper presents a new soft switching system in three-phase voltage source inverters. In the majority of existing soft switching systems, there is a risk of damaging main or auxiliary transistors in the case of disturbances in the control system due to capacitors that are connected in parallel to the main transistors and due to resonant inductors which are connected in series to the auxiliary transistors. In the proposed new soft switching system, a danger of an abrupt discharge of capacitors through a conductive transistor does not occur and there is no risk of the interruption of the inductor current which usually causes damage to transistors. The paper describes the operation principles and the control algorithm of the presented solution, which is much simpler with respect to the control methods in soft switching systems applied by now. The method of the selection of the soft switching system's elements is also briefly described. The operation correctness of the presented system has been confirmed by laboratory research, and attention has been paid to certain limitations of the control system.

   Quasi-resonant switched inverter with integrated sinusoidal filter
By Ingmar KAISER [View]
[Download]

Abstract: Silicon carbide semiconductors offer high switching frequencies for high voltage application which reduces the filter size. The main drawback of high current applications are high turn-on losses. Within this paper an inverter is proposed which uses a quasi-resonant triangular current mode where the MOSFETs are turned on at zero current.

   Solution of Triple Problems in Transformer Windings for Current Resonant Converter with High Power Density and Wide Input Voltage Range
By Seiya ABE [View]
[Download]

Abstract: The realization of wide input voltage and high power density on the conventional current resonant converter such as LLC converter remarkably increases transformer winding loss and its design difficulty. Therefore, it is difficult for the conventional LLC converter to satisfy both requirements. In order to apply the LLC converter with both conditions, this paper investigates the mechanism of the transformer winding loss occurrence in the conventional LLC converter. Moreover, the solution for mentioned above problems is proposed which can removes the transformer design difficulty as well by only changing the resonant operation mode.

   Study on Characteristics of Hybrid Switch using Si IGBT and SiC MOSFET depending on External Parameters
By Satoshi UENO [View]
[Download]

Abstract: A hybrid switch configured by silicon insulated gate bipolar transistor (Si IGBT) and silicon carbide metal-oxide semiconductor field effect transistor (SiC MOSFET) have been investigated to be a cost effectiveness and high efficiency. In this paper, we aimed reducing the hybrid switch loss and expanding operation area of frequency and current. We measured dependency on various parameters to analyze characteristic of hybrid switch. Especially, we focused on Gate option, influence of parasitic inductance and antiparallel diode on Si IGBT. In addition, we proposed a new gate signal option using commutation for hybrid switch. Experimental results show that characteristics of hybrid switch with new gate option and the effects of commutation and external parameters on loss.

   Study on Low-Capacitance Inductors for a High-Frequency Quasi-Z-Source Inverter
By Kornel WOLSKI [View]
[Download]

Abstract: SiC power devices offer a good chance to improve performance of impedance source converters;however, new challenges must be met. This paper presents a study on phenomena occurring due toparasitic capacitances of inductors in a high-frequency quasi-Z-source inverter. Rapid changes ofvoltage values caused by new, fast-switching SiC MOSFETs and Schottky diodes make this issueimportant. Negative influence of the parasitic capacitances on the quality of input current and on theamount of semiconductor switching losses is confirmed via precise Saber Sketch simulations andlaboratory experiments with a 100-kHz/6-kVA model. Furthermore, simple methods of minimizingthe parasitic capacitance values through means of isolation and winding techniques are discussed.

EPE 2017 - DS1d: Hard & Soft Switching techniques I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2017 ECCE Europe - Conference > EPE 2017 - Topic 02: Power Converter Topologies and Design > EPE 2017 - DS1d: Hard & Soft Switching techniques I
	[return to parent folder]

	A Transformer-less Single Phase Inverter For photovoltaic Systems By Ali MOSTAAN	[View] [Download]
Abstract: A single phase transformer-less inverter is introduced in this paper. The negative polarities of the input voltage and output terminal have common ground. Therefore, the leakage current problem that is common in PV systems is eliminated naturally. In addition, the proposed inverter has fewer components compared with its counterparts and only one switch conducts during the active states which enhance the inverter efficiency. The proposed inverter is analyzed in details and compared with some existing topologies. The performance of the proposed inverter is validated using the simulation results.

	Comparison of Switching Devices for a Zero-Current Switched Class E based Automotive Inductive Charging Converter System By Patrick NIEFNECKER	[View] [Download]
Abstract: The zero-current switched Class E converter topologies offer great potential regarding energy efficiency and cost effectiveness for automotive inductive charging applications. In comparison to the Class D converter topologies the resonant current is not flowing in the semiconductor switching devices, reducing the system's sensitivity to variations of the charging-coil coupling. In this paper the performance of SiC MOSFETS are investigated and compared to the performance of a selected Si IGBT. A simplified test set-up with similar behavior as the inductive charging circuit has been developed that allows an accurate adjustment of the operating conditions of the switching devices. The waveforms obtained from the measurements confirm the theoretical predictions very well. It is shown that low switching losses are achieved mainly related to the discharge of the output capacitance of the SiC MOSFET. The results also show the suitability of the proposed topology for the given application.

	Discontinuous Interleaving of Parallel Inverters for Efficiency Improvement By Bjørn RANNESTAD	[View] [Download]
Abstract: Interleaved switching of parallel inverters has previously been proposed for efficiency/size improvements of grid connected three-phase inverters. This paper proposes a novel interleaving method which practically eliminates insulated gate bipolar transistor (IGBT) turn-on losses and drastically reduces diode reverse recovery losses. The reduction in switching losses are obtained by interleaving two parallel inverter branches so that only one branch conducts the load current at a time. By placing saturable inductors between the parallel branches, soft switching may be obtained, and thereby overall power module losses are reduced. The modulation strategy is suited for converters with doubly fed induction generators (DFIG) for wind turbines, but are not limited hereto. Improvement of switching performance are measured and operational efficiency improvements are calculated and verified in an operating inverter.

	Evaluation of GaN Transistors in a Phase-leg Configuration for Motor Drive Applications By Jennifer LAUTNER	[View] [Download]
Abstract: This paper presents the evaluation of a 650V GaN transistor which is used for a motor drive application.The influence of parasitic effects, e.g. cross conduction and stray inductances, in a GaN phase-legconfiguration are analyzed by means of simulation. Additionally, experimental results of the switchingtransients are shown. Furthermore, measurement issues and other practical challenges are discussed

	Loss-Oriented Asymmetrical PWM Technique for High-frequency Impedance Source Converters By Piotr MAJTCZAK	[View] [Download]
Abstract: The paper presents four asymmetrical pulse width modulation techniques for three-phase impedance source converters operating at high switching frequencies. The concept behind all proposed methods is to introduce single-phase shoot-trough states and reduce commutation currents of fast-switching SiC MOSFETs. All techniques are explained and verified by means of Saber simulations and laboratory experiments. Advantages and negative aspects, such as increased on-state losses, are discussed in reference to state-of-the-art techniques. Performed measurements at 100kHz/6kVA model of the quasi-Z-source inverter show that in selected operation areas new techniques lead to slightly improved efficiency without loss of input and output currents quality.

	PROPOSAL OF A NEW SOFT SWITCHING SYSTEM FOR THREE-PHASE VOLTAGE SOURCE INVERTERS By Zbigniew SZULAR	[View] [Download]
Abstract: The paper presents a new soft switching system in three-phase voltage source inverters. In the majority of existing soft switching systems, there is a risk of damaging main or auxiliary transistors in the case of disturbances in the control system due to capacitors that are connected in parallel to the main transistors and due to resonant inductors which are connected in series to the auxiliary transistors. In the proposed new soft switching system, a danger of an abrupt discharge of capacitors through a conductive transistor does not occur and there is no risk of the interruption of the inductor current which usually causes damage to transistors. The paper describes the operation principles and the control algorithm of the presented solution, which is much simpler with respect to the control methods in soft switching systems applied by now. The method of the selection of the soft switching system's elements is also briefly described. The operation correctness of the presented system has been confirmed by laboratory research, and attention has been paid to certain limitations of the control system.

	Quasi-resonant switched inverter with integrated sinusoidal filter By Ingmar KAISER	[View] [Download]
Abstract: Silicon carbide semiconductors offer high switching frequencies for high voltage application which reduces the filter size. The main drawback of high current applications are high turn-on losses. Within this paper an inverter is proposed which uses a quasi-resonant triangular current mode where the MOSFETs are turned on at zero current.

	Solution of Triple Problems in Transformer Windings for Current Resonant Converter with High Power Density and Wide Input Voltage Range By Seiya ABE	[View] [Download]
Abstract: The realization of wide input voltage and high power density on the conventional current resonant converter such as LLC converter remarkably increases transformer winding loss and its design difficulty. Therefore, it is difficult for the conventional LLC converter to satisfy both requirements. In order to apply the LLC converter with both conditions, this paper investigates the mechanism of the transformer winding loss occurrence in the conventional LLC converter. Moreover, the solution for mentioned above problems is proposed which can removes the transformer design difficulty as well by only changing the resonant operation mode.

	Study on Characteristics of Hybrid Switch using Si IGBT and SiC MOSFET depending on External Parameters By Satoshi UENO	[View] [Download]
Abstract: A hybrid switch configured by silicon insulated gate bipolar transistor (Si IGBT) and silicon carbide metal-oxide semiconductor field effect transistor (SiC MOSFET) have been investigated to be a cost effectiveness and high efficiency. In this paper, we aimed reducing the hybrid switch loss and expanding operation area of frequency and current. We measured dependency on various parameters to analyze characteristic of hybrid switch. Especially, we focused on Gate option, influence of parasitic inductance and antiparallel diode on Si IGBT. In addition, we proposed a new gate signal option using commutation for hybrid switch. Experimental results show that characteristics of hybrid switch with new gate option and the effects of commutation and external parameters on loss.

	Study on Low-Capacitance Inductors for a High-Frequency Quasi-Z-Source Inverter By Kornel WOLSKI	[View] [Download]
Abstract: SiC power devices offer a good chance to improve performance of impedance source converters;however, new challenges must be met. This paper presents a study on phenomena occurring due toparasitic capacitances of inductors in a high-frequency quasi-Z-source inverter. Rapid changes ofvoltage values caused by new, fast-switching SiC MOSFETs and Schottky diodes make this issueimportant. Negative influence of the parasitic capacitances on the quality of input current and on theamount of semiconductor switching losses is confirmed via precise Saber Sketch simulations andlaboratory experiments with a 100-kHz/6-kVA model. Furthermore, simple methods of minimizingthe parasitic capacitance values through means of isolation and winding techniques are discussed.